How big was the event?

Sunday's event, promoted by British Athletics and attended by a number of big names from around the world, generated the second biggest crowd for a Paralympic event outside of the Olympics.

The day's action inside the Olympic Stadium featured British Paralympians, including Jonnie Peacock, Richard Whitehead, David Weir and Hannah Cockroft, taking on the world's best para-athletes.

It was broadcast live on Channel 4, BBC World Service and BBC Radio 5 live.

Any notable achievements?

Paralympic hopefuls for Rio 2016 Sophie Hahn and Georgie Hermitage both impressed as they set new world records in quick succession.

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'I run to inspire my daughter' - Hermitage

Hermitage, 26, set a new best in the T37 400m with 18-year-old Hahn clocking 13 seconds in the T38 100m.

There were also wins for 2012 gold medallists Whitehead (T42 200m), Cockroft (T34 400m) as well as Commonwealth Games gold medallist Libby Clegg and guide Mikail Huggins (T12 200m) and club thrower Jo Butterfield who improved her own F51 European record by almost two metres.

But amputee sprinter Peacock was edged out by American rival Richard Browne in the T44 100m, while Weir was a disappointing fifth in the T54 1500m, which was won by Switzerland's Marcel Hug, after a recent illness.

So why the low attendance?

Double Paralympic gold medallist Cockcroft and Paralympic 100m champion Peacock joined Weir in suggesting more could have been done to boost interest in the event.

Weir said: "I don't think it was promoted well enough. It all looked as though it was geared towards Friday and Saturday. The crowd that were there were fantastic though.

"I am a big believer we need to be in the public's faces all the time. After Rio in 2013, we had 60,000 in here. It will die because we are not on TV every week, we are not in the Diamond League, we are not in newspapers.

"We have big races in Switzerland that has no stadium round it, no one televises it. We need to be in the public eye all the time. Maybe putting these races on TV will boost our ticket sales."

Weir said that British Athletics promoted the event "as best they could", but called on the IPC to do more.

Cockcroft said the Diamond League had so much promotion, the Sunday had been "overshadowed", while Peacock accused organisers of "dropping the ball".

"I don't think momentum has been lost," said Cockcroft. "The downfall here was publicising the event.

"Given the right time, the right day, the right chance, we could fill the stadium again."

What did the organisers say?

A statement from British Athletics said: "We're delighted with the support that the athletes received at today's Sainsbury's Anniversary Games. There was an uptake of 20,000 tickets for the day, one of the biggest ever crowds for a para-athletics event outside of the Paralympic Games in 2012."

Director of communications for the IPC, Craig Spence, believes the sport has taken a step in the right direction.

He said: "If you had said to us in 2011 that an event in 2015 would get 20,000 spectators, with 150 of the best athletes in the world, with prize money, paid accommodation and live on TV, every single athlete would have bitten your hand off. We are a victim of our own success.

"This is a long journey and we have grown very quickly. Maybe athletes need to put it into perspective.

"For some, that would have been the biggest crowd they have ever performed in front of."

Peacock lost his fourth consecutive race against Browne

Is there an obvious solution?

Weir and Cockcroft suggested combining Paralympic events within Diamond League meetings, but Spence believes that would cause its own problems.

"Why couldn't we race late morning Saturday?," said Weir. "People could have got double their money and it is athletics, not Paralympics. People come and watch athletics."

Cockcroft added: "I don't want the Olympics and Paralympics to merge because I am proud of what we have made of that name but it would be amazing to gain some new fans who didn't know we were there."

Spence said: "That is a conversation we would have to have with the International Association of Athletics Federations (IAAF). The danger is if you integrate events, you would get spectators but would you get the media coverage? You have to be realistic."

Social media reaction

Amputee sprinter Jonnie Peacock thanked the crowds on Twitter

Scottish Paralympic sprinter Libby Clegg also tweeted her gratitude for the support